In the past, one method of providing a division type circuit is to generate a binary reciprocal of an input, X, and multiply the reciprocal by another input, Y, to produce a quotient Y/X. The uniqueness of this method lies in the manner of generating the reciprocal of X. It is known in the prior art, see for example U.S. Pat. No. 3,828,175, entitled "Method and Apparatus for Division Employing Table-Lookup and Functional Iteration", issued Aug. 6, 1974, that a table-lookup can be utilized which has stored therein all of the possible values of 1/X for the entire range of X to be utilized. The major problem with this type of apparatus is the size of lookup table (or amount of storage) that must be provided. For example, if the system uses a relatively standard 16 bit word as the X input and the range of interest is from 16,384 to 32,767, the system must be capable of storing 16,384 16 bit words or 262,144 bits of storage must be provied.
It will of course be undertood that it is desirable to have the capability of generating other types of functions (besides 1/X) and that these other generated functions might be utilized in mathematical operations in a fashion similar to the use of the reciprocal function discussed above. In the generation of the curve of a function in the X-Y plane, approximations such as the Taylor series expansion are known but these approximations, in general, incorporate such a large error that they are not acceptable for most of the present day mathematical operations.